Hammer



FIG. 1 is a front perspective view of a hammer showing my new design;

FIG. 2 is a rear perspective view, taken from below, thereof;

FIG. 3 is a side elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a back elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines are for environmental purposes only and form no part of the claimed design. 

The ornamental design for a hammer, as shown. 